Extended valid __getitem__behaviour on AttrTree for root nodes
Extended valid __getitem__behaviour on AttrTree for root nodes

ioam/holoviews,vascotenner/holoviews,basnijholt/holoviews,mjabri/holoviews,mjabri/holoviews,mjabri/holoviews,vascotenner/holoviews,ioam/holoviews,basnijholt/holoviews,vascotenner/holoviews,basnijholt/holoviews,ioam/holoviews